Introduction to Houseplants

Introduction to Houseplants
General Master Gardener Training
By Lisa Johnson
Dane County UWEX
Horticulture Educator
In Praise of Houseplants...
Houseplants
• Houseplants recycle CO2 and give
off O2
– 1-2 medium houseplants per 100ft2
– NASA: Spathiphyllum one of the best
• Houseplants remove VOC’s
• Houseplants
H
l
add
dd humidity
h idi to dry
d air
i
• Mental/emotional benefits
Tips to Consider When Shopping
• M
Match
t h plants
l t to
t the
th environment
i
t you have
h
• Check roots
– tug test
– circling roots
• Check for insects
– Spider mites on palms, ivies, calatheas
• Do not expose to temperatures below 50ºF
– Have plants wrapped
wrapped, warm up car if very cold
When you get your plant home
• Acclimation process
–
–
–
–
–
–
8 weeks (2 months)
Hibiscus, gardenias: loss of buds and leaves
Vanishing variegation
Yellowingg and leaf loss
Brown crispy margins
Scorching
• Cleaning
– Remove p
pesticide and other residues,, p
plus
dust
Watering
• Overwatering is the number one killer of
houseplants!
• Watering tips
– Water by WEIGHT
– Wate
Water thoroughly
t o oug y w
when
e you do wate
water,, allowing
a ow g
plants to dry sufficiently between waterings
– Do not allow plants to sit in water a long time
– Use appropriate potting media
– Fluoride, chlorine in water
– Using rainwater is not recommended
Watering
How to Repot ?
™Take the plant out of
d
decorative
ti container
t i
™Use clean grow pot
™New pot should be only
1 inch larger than old
pot
™Lay plant
™L
l
gently
l
on side and
remove from
f
pot
™Loosen roots
™Check for
damage or rot
™Prune roots as
necessary
™Use a sterilized potting
p
g
mix containing, peat,
compost, vermiculite
and/or
d/ perlite
lit
™Press soil mix into roots
t fill all
to
ll air
i pockets
k ts
™Keep plant at same level
as it was in old pot
™Water gently
™L t drain
™Let
d i th
through
h
™Return to decorative
container
Double Pott
Potting
ng
Decorative
Container
Grow Pot
Florist’ss
Florist
Foam
Wicking
(optional)
Tips for Using the Double Potting Method
™Decorative
™D
ti containers
t i
are waterproof
t
f with
ith no
drainage holes.
™Grow pots are generally plastic pots with multiple
drainage holes.
™Wicking is optional and can be used for bottom
watering. Insert 2/3 up into grow pot.
™Place florist’s
florist s foam on the bottom of the
decorative container.
™Place grow pot on top of florist
florist’ss foam
foam.
™Water till drains. Florist foam absorbs excess.
™Do not submerge roots (bottom of grow pot) in
water!
Soil and Re-potting
• Use houseplant potting soil (it may actually
be a soil-less mix).
mix)
• Houseplants, especially starter plants may
be pot bound when you buy them
them.
• The new pot should not be more than two
inches in diameter larger than the old pot.
pot
• Leave 1/2” to 1” for water collection, ie.
don’tt fill the pot to the top with soil.
don
soil
• Plant at the same level as the old pot.
• Some plants ‘like’ to be pot bound
bound.
– Christmas cactus, aloe, jade, cacti, etc.
Re potting
Re-potting
Fertilizer
• Especially if using soil-less
soil less media,
media fertilizer
is important.
• Fertilize once or twice a month (dilute)
(dilute).
• Avoid over-fertilizing.
• Soluble
S
salt buildup.
i
• Blooming houseplants may need more P.
• In general, do not fertilize DecemberFebruary IF using natural light.
Light Levels (after a week)
Not Enough Light Perfect Light
Too Much Light
No growth
New growth
Leaves yellowing
Dark green
leaves
Few leaves
dropping
St
Strong
variegation
R
Regular
l water
t
needed
New growth
different
Pale, near white
leaves
Leaves dropping
Leaves dropping
Loss off
L
variegation
S il stays
Soil
t
wett
S
Scorched
h d lleaves
Soil
S
il dries
d i outt
quickly
Light Levels
East
Window
M
Morning
i
light
C l
Cool
West
Window
Af
Afternoon
light
W
Warm
South
North
Window
Window
All day
d sun Filtered
Fil
d
light
H t
Hot
C l
Cool
2/3 light
g of
south
window
2/3 light
g of
south
window
Intense
1/5 light
g of
south
window
Houseplant
p
Maintenance
z
Dust on the leaves
res lts in 25%
results
reduction in light
interception
Houseplant Maintenance
• Dusting also helps
in insect control
• Wipe the leaves
gently with a soft
cloth
• ‘Bathe’
Bathe hairyleaved plants
rather than
dusting
• Leaf shine
products?
When Bringing Houseplants
Indoors in Autumn
• Hose off
off,
then after
the plant is
dry, spray
with
insecticidal
soap if
tolerated on
that plant
species
i
Houseplant Diseases
• Powdery mildew and root rots are two
major
j p
problems
• Try cultural changes before resorting to
chemical products
• Know your plant
Powdery
y Mildew
• Begonia, Kalanchöe and
rosemary are especially
susceptible
• Tryy reducingg humidityy and
increasing air flow
• Can use 1 1/2 TBS baking soda
& 3 TBS horticultural oil in 1
gallon of water
• Fungicides containing
myclobutanil, and labeled for
use on houseplants may help
Root Rots
• Symptoms include the
soil
il staying
i wet, yellowing,
ll i
wilting leaves, stunting,
and
d soft,
f b
brown b
badd
smelling roots
• Many soil-borne fungi
cause root rot
• Best to discard the plant
Houseplant Insect Pests
•
•
•
•
•
•
•
•
Mealybugs
Aphids
Thrips
Spider
p
mites
Whiteflies
Scales
Fungus gnats
Springtails
Mealy bugs
• Mealybugs can infest all
plant parts
parts, including the
roots.
• They produce a waxy
coating on their bodies and
their egg masses that resist
i
insecticides.
ti id
• If the infestation is light,
use Q-tips™
Q-tips dipped in
rubbing alcohol, or use
sprays with bifenthrin,
permethrin
i or resmethrin.
i
Mealybugs.
Aphids
p
• Aphids are softbodied, sucking
i
insects
that
h feed
f d on
plant sap
• Th
They can b
be
controlled on
houseplants with
insecticidal soap &
forceful water
sprays or
products with
bifenthrin,,
permethrin or
resmethrin
Thrips
• Thrips are 1⁄16” long and
fast. They hide in flower
& leaf buds, and are
hard to find.
• Thrips cause feeding
d
damage
and
d vector
t plant
l t
viruses.
• Washing, bifenthrin,
permethrin, resmethrin,
pyrethrins, insecticidal
soap, neem oil,
il plant
l t oil
il
extracts (at least two
applications
pp
sprayed
p y
once every 5 days are
usually necessary).
Spider mites
• Spider mites are oval
and yellowish. They are
very tiny,
i
only
l 1/50th”
1/50 h”
long, salt-grain size.
• They feed under leaves,
leaves
sucking plant sap,
causingg stippling
pp g or
bronzing of leaves.
• Populations increase
rapidly.
idl
• Discard the plant or use
products with bifenthrin
or insecticidal soap.
White Flies
• Whiteflies have
piercing/sucking
mouthparts.
• They feed & lay eggs
on the
th underside
d id off
leaves.
• Washing, bifenthrin,
permethrin, at least
three applications
sprayed
d once every 5
days.
• Neem oil.
oil
An adult whitefly.
Scales
• Often on ferns, orchids,
schefflera zebra plant,
schefflera,
plant
weeping fig and ivy
• Have hard shells that
repel insecticides
• Found under leaves on
l f veins
leaf
i and
d petioles
ti l
• Wash plants, scrape off
scales or use sprays with
bifenthrin, permethrin or
resmethrin.
Fungus gnats
• Often mistaken for
fruit flies, but live in
soil and eat organic
matter
• Unless large
populations build up,
they do very little
d
damage
tto plants
l t
• Can use the ‘potato
slice’ method to get rid
slice
of them
• Also can let soil dryy out
more between
waterings
Springtails
• Springtails are scavengers
that eat decaying organic
matter in soil. Rarely
damage plants
• Named for forked
‘furcula’ that allows them
to jump
• Like damp places
• Let soil dry as much as
possible between
waterings to get rid of
springtails.
Springtails.
Easy to Care
are for
Plant Selections
African Violet
•
•
•
•
•
•
Saintpaulia ionantha
Gesneriaceae
The African violet was first
discovered in East Africa in
1892 by Baron Walter von St.
Paul.
Paul
Best under grow lights
East window
Highly organic soil
Propagate by leaf cuttings in
spring
g ,p
powdery
y mildew,,
Mealyy bugs,
cyclamen mite and stem or
crown rot can be problems.
Alocasia, Amazon Lily
Alocasia x Amazonica
Araceae
• F
From southern
th
A
Asia,
i
throughout South
Pacific
• Propagate by
division
• Some get very large
• Calcium oxalate
crystals
l -- caution
i
• Low light, medium
humidity
Aloe
Aloe vera
Liliaceae (Asphodelaceae)
• From Africa
• Maritime sands and
rocks
• Medical claims
• Medium
M di
to
t high
hi h light
li ht
• Ave. house humidity
• Few
Fe problems
• Do NOT overwater
or over fertilize
Calathea
Calathea spp.
spp
Marantaceae
• From Brazil and
tropical America
• Need low light and
high humidity
• Keep moist, but no
wet feet; will rot
• Can’t go below 55°F
• Don’t
D ’ lik
like d
drafts
f
• Spider mites a
problem
Chinese Evergreen
Aglaonema commutatum
Araceae
• From tropical Asia
and Africa
• Low
L li
light,
ht low
l
humidity ok
• Propagate
P
t by
b
division
• Good for air cleaning
Chinese Evergreen
Aglaonema
modestum
d t
™ Light: medium
™ Water:
W t
moist
i t to
t
dry, well drained
™ Problem:
P bl
overwatering
™ Solution:
lightweight soil
mixture, let drain
completely
mpl t l
Croton
Codiaeum variegatum
Euphorbiaceae
• From the Malaccan Islands
Islands,
Malaysia, Pacific Islands,
southern Asia
• High light, high humidity
• Regular fertilization
• Like to be somewhat potbound
• Should not dry out
• If leaves turn brown and dry
dry, it
is too hot and/or dry
• If lower leaves fall,, air is too dryy
• Thrips, scale, mealybug, spider
mites
Dieffenbachia, Dumb Cane
Dieffenbachia spp.
Araceae
• F
From Mexico,
M i
Columbia, Brazil,
Puerto Rico
• Calcium oxalate –
caution
• Medium light , low
humidity ok
• Too
T much
h ffertilizer
ili
causes marginal leaf
burn
• Air layering
Striped Dracaena
Dracaena deremensis ‘Warneckii’
Warneckii
Dracaena deremensis ‘Lemon-Lime’
Agavaceae
• From tropical Africa
• Leaves narrower
than D. fragrans,
pointy
i t
• Good for air cleaning
• Same cultural care as
D. fragrans
Dracaena, Madagascar Dragon Tree
Dracaena marginata
Agavaceae
•
•
•
•
•
From Madagascar
Can grow to 15’
Air layering
Medium to bright light
Allow to dry out a little,
but leaves may brown if
soil is too dry or light too
bright
Dracaena
Dracaena deremensis
‘Janet Craig’
™Light: low to moderate
y, well drained
™Water: dry,
™Problem: overwatering
™S l i
™Solution:
llet d
dry
completely between
waterings
Dracaena marginata
Dracaena deremensis
‘Janet Craig’
Pleomele reflexa
English Ivy
Hedera helix
Araliaceae
•
•
•
•
•
•
From Eurasia
p
Is poisonous
Stem cuttings
g to medium light
g
Bright
Spider mites a big pest
Invasiveness on West
Coast of U.S.
Bird’s nest fern
Asplenium nidus
• From India, Japan,
Australia
• Somewhat hard to
g
grow
• Low to medium light
• High humidity
• Do not overwater, do
not let gget too dry
y
• Water at base
• Scale
• Likes acidic pH
Weeping fig
Ficus benjamina
Moraceae
• F
From India,
I di Southeast
S th t
Asia, northern tropical
Australia
• Likes high humidity
• Do not overwater
• Bright to medium light,
but not south
• Does not like drafts
• Scale, mealybugs, spider
mites
it
Ficus species
Ficus species
™Light: bright, indirect
™Water: moist
moist, well
drained
™Problem: changing
environment
™Solution: find a bright
location and leave it
th
there!
! Turn
Tu n regularly.
ul l
Ficus lyrata
Ficus maclellandii‘Alii’
Ficus nitida
Ficus benjamina ‘Variegata’
™Ficus elastica
™Ficus maclellandii ‘Alii’
Alii
™Ficus benjamina ‘Variegata’
™Ficus
Fi
b
benjamina
j i
Tropical hibiscus
Hibiscus rosa-sinensis
rosa sinensis
Malvaceae
• From Asia and
Pacific Islands
• Needs LOTS of light
• Cut back when take
indoors for winter
• High humidity
• Spider mites, scale,
aphids, white flies
• Fertility important
Jade Plant
Crassula argentea
Crassulaceae
•
•
•
•
•
•
•
From Africa
Do NOT overwater
Bright to medium light
Leaf or stem cuttings
Low humidity ok
Scale, mealybug
Don’t fertilize Oct-Feb.,
sparingly at other times
• Flowering,
Fl
i
maturity
t it and
d
tight roots
Kalanchöe
Kalanchoe blossfeldiana
Crassulaceae
• From Madagascar
• Light levels low,
medium or high
• Fertilize every 3
weeks when in flower
• Prefers cool temps.
• Powdery mildew,
mildew
scale, mealybugs
• Undemandingg
Palms
Chamaedorea elegans
‘Neanthe Bella’
™Light: low to moderate
™Water: moist, well
d i d
drained
™Problem: spider mites
™Solution: regular,
lukewarm
m water baths
Phoenix roebelinii
Rhapis excelsa
Additional
problem with
palms
Cats love
them
Peace Lily
Spathiphyllum wallisii
Araceae
• From Central
America, Indonesia,
and
d the
th Philippines
Phili i
• Low to medium light
• Shiny
Shi ffoliage
li
• Best for air cleaning
• Division
• Prefer high humidity
for best flower
production
Philodendron
Philodendron scandens oxycardium
Araceae
• From Mexico
• Low light to medium
light
• Poisonous–calcium
oxalate crystals
• Stem cuttings
• Few problems
Pothos, Devil’s ivy
Epipremnum aureum
Araceae
•
•
•
•
•
•
•
From southeast Asia
Low to medium light
Poisonous
Stem cuttings
Undemanding
p
Few problems
Keep on the dry side
Sansevieria, Mother-in-law’s tongue
Sansevieria trifasciata
Agavaceae
• From Indonesia,
India, tropical Africa
• Do not overwater
• Divisions
• Few problems
p heavy
y
• Top
• Undemanding
Spider plant
Chl
Chlorophytum
h t
commosum
Liliaceae
• From coastal South
Africa
• Medium to bright to
low light
• Division, offshoots
• Watering
• Fertilizer cautions